These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 78 insertions, 28 deletions

diff --git a/kernel/arch/arc/mm/init.c b/kernel/arch/arc/mm/init.c
index d44eedd8c..7d2c4fbf4 100644
--- a/kernel/arch/arc/mm/init.c
+++ b/kernel/arch/arc/mm/init.c
@@ -15,6 +15,7 @@
 #endif
 #include <linux/swap.h>
 #include <linux/module.h>
+#include <linux/highmem.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
 #include <asm/sections.h>
@@ -24,16 +25,22 @@ pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 EXPORT_SYMBOL(empty_zero_page);
 
-/* Default tot mem from .config */
-static unsigned long arc_mem_sz = 0x20000000;  /* some default */
+static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE;
+static unsigned long low_mem_sz;
+
+#ifdef CONFIG_HIGHMEM
+static unsigned long min_high_pfn;
+static u64 high_mem_start;
+static u64 high_mem_sz;
+#endif
 
 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
 static int __init setup_mem_sz(char *str)
 {
-	arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
+	low_mem_sz = memparse(str, NULL) & PAGE_MASK;
 
 	/* early console might not be setup yet - it will show up later */
-	pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
+	pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
 
 	return 0;
 }
@@ -41,8 +48,24 @@ early_param("mem", setup_mem_sz);
 
 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 {
-	arc_mem_sz = size & PAGE_MASK;
-	pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz));
+	int in_use = 0;
+
+	if (!low_mem_sz) {
+		if (base != low_mem_start)
+			panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
+
+		low_mem_sz = size;
+		in_use = 1;
+	} else {
+#ifdef CONFIG_HIGHMEM
+		high_mem_start = base;
+		high_mem_sz = size;
+		in_use = 1;
+#endif
+	}
+
+	pr_info("Memory @ %llx [%lldM] %s\n",
+		base, TO_MB(size), !in_use ? "Not used":"");
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -72,46 +95,62 @@ early_param("initrd", early_initrd);
 void __init setup_arch_memory(void)
 {
 	unsigned long zones_size[MAX_NR_ZONES];
-	unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
+	unsigned long zones_holes[MAX_NR_ZONES];
 
 	init_mm.start_code = (unsigned long)_text;
 	init_mm.end_code = (unsigned long)_etext;
 	init_mm.end_data = (unsigned long)_edata;
 	init_mm.brk = (unsigned long)_end;
 
-	/*
-	 * We do it here, so that memory is correctly instantiated
-	 * even if "mem=xxx" cmline over-ride is given and/or
-	 * DT has memory node. Each causes an update to @arc_mem_sz
-	 * and we finally add memory one here
-	 */
-	memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
-
-	/*------------- externs in mm need setting up ---------------*/
-
 	/* first page of system - kernel .vector starts here */
 	min_low_pfn = ARCH_PFN_OFFSET;
 
-	/* Last usable page of low mem (no HIGHMEM yet for ARC port) */
-	max_low_pfn = max_pfn = PFN_DOWN(end_mem);
+	/* Last usable page of low mem */
+	max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 
-	max_mapnr = max_low_pfn - min_low_pfn;
+#ifdef CONFIG_HIGHMEM
+	min_high_pfn = PFN_DOWN(high_mem_start);
+	max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
+#endif
+
+	max_mapnr = max_pfn - min_low_pfn;
 
-	/*------------- reserve kernel image -----------------------*/
-	memblock_reserve(CONFIG_LINUX_LINK_BASE,
-			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
+	/*------------- bootmem allocator setup -----------------------*/
+
+	/*
+	 * seed the bootmem allocator after any DT memory node parsing or
+	 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
+	 *
+	 * Only low mem is added, otherwise we have crashes when allocating
+	 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
+	 * avail memory, ending in highmem with a > 32-bit address. However
+	 * it then tries to memset it with a truncaed 32-bit handle, causing
+	 * the crash
+	 */
+
+	memblock_add(low_mem_start, low_mem_sz);
+	memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 
 #ifdef CONFIG_BLK_DEV_INITRD
-	/*------------- reserve initrd image -----------------------*/
 	if (initrd_start)
 		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 #endif
 
 	memblock_dump_all();
 
-	/*-------------- node setup --------------------------------*/
+	/*----------------- node/zones setup --------------------------*/
 	memset(zones_size, 0, sizeof(zones_size));
-	zones_size[ZONE_NORMAL] = max_mapnr;
+	memset(zones_holes, 0, sizeof(zones_holes));
+
+	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
+	zones_holes[ZONE_NORMAL] = 0;
+
+#ifdef CONFIG_HIGHMEM
+	zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
+
+	/* This handles the peripheral address space hole */
+	zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
+#endif
 
 	/*
 	 * We can't use the helper free_area_init(zones[]) because it uses
@@ -122,9 +161,12 @@ void __init setup_arch_memory(void)
 	free_area_init_node(0,			/* node-id */
 			    zones_size,		/* num pages per zone */
 			    min_low_pfn,	/* first pfn of node */
-			    NULL);		/* NO holes */
+			    zones_holes);	/* holes */
 
-	high_memory = (void *)end_mem;
+#ifdef CONFIG_HIGHMEM
+	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
+	kmap_init();
+#endif
 }
 
 /*
@@ -135,6 +177,14 @@ void __init setup_arch_memory(void)
  */
 void __init mem_init(void)
 {
+#ifdef CONFIG_HIGHMEM
+	unsigned long tmp;
+
+	reset_all_zones_managed_pages();
+	for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
+		free_highmem_page(pfn_to_page(tmp));
+#endif
+
 	free_all_bootmem();
 	mem_init_print_info(NULL);
 }